There is only ONE Gospel, Galatians 1:6-7.
Water baptism is not a work.
Jesus told his disciples to go, make disciples and baptise. Adult baptism is an outward sign of what has happened to us spiritually; we die to sin, (go under the water) and rise to new life with Christ, (are brought back out again).
Communion is a response to Jesus' command to "do this in memory of me."
They are both responses to God's grace - things that we do to show that we ARE saved, not things we do in order to BE saved.
Indeed, there is only one Gospel according to St. Paul, this was initially preached orally by the Apostles but later written down by at least two of them, St. Matthew and St. John the Beloved Disciple, who also composed three Epistles and the Apocalypse, and then St. Mark, the owner of the house containing the Cenacle, and a disciple of St. Peter, later the first bishop of Alexandria, composed his Gospel, and St. Luke, a disciple of Paul, composed a Gospel text and the Acts of the Apostles. All four of these represent the One Gospel and when the Church began adopting a canon of the New Testament in response to forgeries and corruptions like the disgusting blasphemous “Infancy Gospel of Thomas” authored by the Manichaeans, the corrupt version of Luke and a subset of the Pauline Epistles used by the Marcionites, the false “Gospel of the Ebionites” used by the eponymous sect, the Tripartite Tractate composed by the Valentinians, the blasphemous Acts of John, the blasphemous Gospel of Judas, the corrupt Acts of Andrew and Acts of Thomas, and other psuedepigrapha like 1 Barnabas, which is not inherently heretical, and came closer than the rest of the psuedepigrapha to making it into the canon, but it was realized that the work was too obviously reflective of the exegetical method of the Catechtical School of Alexandria, and we don’t know that St. Barnabas was ever in Alexandria.
There is also a lost Gospel of the Hebrews, which is probably the original Aramaic version of Matthew, and possibly an orthodox Gospel according to Thomas that records the sayings of our Lord, but survives only in a form with heretical interpolations reflecting some Gnostic sect (if you were to purge these, you would have a list of sayings compatible with the three Synoptic Gospels, Mark, Matthew and Luke). Then there is the Gospel According to Peter, which is probably psuedepigraphical, although it could have been someone else put to writing St. Peter’s narration of the One Gospel, which survives only in a fragment that provides a vivid account of the Passion of our Lord, but gets a little weird towards the end with a Resurrection narrative featuring angels whose heads extended into the heavens and the Holy Cross floating around and speaking, which is possible, since the relics of the Holy Cross are known for miraculous healings, and in traditional Christianity we venerate, but do not worship, the Cross, just as we venerate the saints, icons of our Lord, and the Holy Bible or the Evangelion (Gospel Book). Then there is the Gospel According to Nicodemus, which may be legitimate or a pious forgery, and the Infancy Gospel of James, which reflects authentic Orthodox and Roman Catholic doctrine concerning the nativity and pregnancy of the Blessed Virgin Mary, but whose apostolic provenance was doubted by the early Church, although the work remained popular into the Middle Ages.
Of the four canonical Gospels, scholarship indicates that Mark was written first, followed by Luke-Acts and Matthew, and then the John. The tradition of the Church agrees, except it talks about Matthew being written in the Hebrew tongue (presumably Aramaic and not actually Hebrew, which was only a liturgical language by the time of Christ; its recent revival into the vernacular tongue of the State of Israel is an impressive national achievement). This I suspect is the Gospel of the Hebrews which survives only in quotes from the Church Fathers.
But together with the Pauline, Petrine, Lukan and Johannine writings, the unknown author of the Hebrews (widely considered to be St. Paul), and the epistles of Saints James and Jude, these collectively convey the Gospel handed down once to the Fathers, which is prophesied in the Old Testament.
Galatians 1:6-7 to reiterate states there is only one Gospel, and Galatians 1:8-9 states that anyone preaching another Gospel is anathema.
